IAOx induces the SUR phenotype and differential signalling from IAA under different types of nitrogen nutrition in Medicago truncatula roots

Indole-3-acetaldoxime (IAOx) is a particularly relevant molecule as an intermediate in the pathway for tryptophan-dependent auxin biosynthesis. The role of IAOx in growth-signalling and root phenotype is poorly studied in cruciferous plants and mostly unknown in non-cruciferous plants. We synthesize...

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Detalles Bibliográficos
Autores: Buezo, J., Esteban, R., Cornejo, A., López-Gómez, Pedro, Marino, D., Chamizo-Ampudia, A., Gil, M. J., Martínez-Merino, V., Moran, J. F.
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/61433
Acceso en línea:http://hdl.handle.net/10810/61433
Access Level:acceso abierto
Palabra clave:Ammonium
Auxin
CYP71A
Indole-3-acetaldehyde oxidase
Indole-3-acetaldoxime
Nitrate
Oximes
Phenotype
Root
Superroot
Urea
Descripción
Sumario:Indole-3-acetaldoxime (IAOx) is a particularly relevant molecule as an intermediate in the pathway for tryptophan-dependent auxin biosynthesis. The role of IAOx in growth-signalling and root phenotype is poorly studied in cruciferous plants and mostly unknown in non-cruciferous plants. We synthesized IAOx and applied it to M. truncatula plants grown axenically with NO3 -, NH4 + or urea as the sole nitrogen source. During 14 days of growth, we demonstrated that IAOx induced an increase in the number of lateral roots, especially under NH4 + nutrition, while elongation of the main root was inhibited. This phenotype is similar to the phenotype known as superroot previously described in SUR1- and SUR2-defective Arabidopsis mutants. The effect of IAOx, IAA or the combination of both on the root phenotype was different and dependent on the type of N-nutrition. Our results also showed the endogenous importance of IAOx in a legume plant in relation to IAA metabolism, and suggested IAOx long-distance transport depending on the nitrogen source provided. Finally, our results point out to CYP71A as the major responsible enzymes for IAA synthesis from IAOx, while they exclude indole-3-acetaldehyde oxidases. © 2019 Elsevier B.V.